To secure the safety of such vehicles and systems, including an aging aircraft, which have been used for a long time, it is necessary to minimize a heat risk on a structure (fuel pipes, hydraulic pipes, fuel tanks, and the like) which allows an inflammable liquid to pass through.
The wiring is often designed such that electric wires at different potentials are bound into a single bundle. In an electric wire bundle of this type, adjacent electric wires rub against one another due to aircraft vibrations and the like. There is a risk that the rubbing of the electric wires for a long time may cause further wear of insulations of the electric wires, eventually resulting in an arc fault occurring between electric wires, particularly power supply wires (power wires), at different potentials within the electric wire bundle.
As a first measure to counter the risk, an arc fault circuit breaker is employed which is designed to determine whether or not an electric arc occurs based on the waveform of the electric current or voltage, and to be capable of disconnecting circuits in a moment once the electric arc occurs.
As a second measure to counter the risk, a method is employed in which: electric wires at different potentials are spaced out; and each group of electric wires at the same potential are bound into a single electric wire bundle. This method can eliminate a risk that wires wear due to their rubbing, and minimize a risk of the occurrence of an electric arc.
As a third measure to counter the risk, electric wires are protected by winding an ark protection sleeve around the electric wires in a predetermined length.